Sickle bar cutters involve section blades secured by rivets to a cutter bar which is adapted to reciprocate back and forth in a groove provided therefor in the sickle bar. The section blades interact with a ledger plate associated with a guard to cut standing crop or the like. The sickle section blades are subject to damage and wear and must be periodically replaced A common method of doing so is to remove the cutting bar from the sickle bar by disconnecting the cutting bar from its connection to the driving pitman, placing the cutting bar on an anvil disposed at a different location to remove one or more of the section blades and rivet a new section blade in place thereof. This is a time comsuming procedure.